Geothermal Facts

California produces more electricity from geothermal resources than any other state or country.

About 4.5 percent of California’s total electrical power generation in 2012 (about 13,000 Gigawatt hours) came from geothermal resources, according to the California Energy Commission.

Six California counties produced geothermal resources hot enough for electrical power generation in 2012.

In 2012, geothermal resources generated more than five times the electricity in California than the state’s solar power plants, according to the California Energy Commission.

Geothermal Fields

California’s deepest producing geothermal well is over 2 miles deep and located in The Geysers Geothermal field, about 60 miles northeast of San Francisco.

Presidents Ulysses S. Grant, William Howard Taft, Theodore Roosevelt, Franklin D. Roosevelt, and Gerald Ford all visited The Geysers. The first four saw it as a world-famous resort and the last as a modern geothermal field.

A well drilled in the 1920s at The Geysers was named “Whistling Annie.” Once the hot springs and fumaroles had fanciful names, including “The Devil’s Wash Tub,” the “Witches’ Cauldron,” and “Lemonade Spring.”

Drilled in Southern California’s Salton Sea Geothermal field, well “Vonderahe”1 is one of the largest and hottest geothermal wells in the world. It can produce nearly 2.2 million pounds of hot water in an hour, enough to power a 30-megawatt power plant.

Geothermal waters produced from the Salton Sea Geothermal field can have total dissolved solids reaching 250,000 parts per million, about seven times higher than sea water.

The City of San Bernardino has a space-heating project that is the largest geothermal direct-use project in North America—heating 37 buildings, including a 15-story high-rise and government facilities. The geothermal water runs through 15 miles of pipelines.

Geothermal drinking water is bottled and sold by a company in Calistoga.